Flat warp knitting machines



Nov. 7, 1961 A. w. H. PORTER 3,007,326

FLAT WARP KNITTING MACHINES Filed March 28, 1960 United States Patent3,007,326 FLAT WARP KNITTING MAtIIWES Allan William Henry Porter,Burton-on-Trent, England, assignor to Hobourn-F.N.lF. Limited Filed Mar.28, 1960, Ser. No. 18,116 Claims priority, application Great BritainApr. 14, 1959 8 tjlaims. (Cl. 66-109) This invention relates to sinkerassemblies for fiat warp knitting machines of the kind which include astraight row of reciprocating hooked needles between which the sinkers,which consist of fiat plates, are situated.

The sinkers are reciprocated to and fro so that nebs on their upperedges are moved between a first position in which they lie across therow of needles and fit between the individual needles and a secondposition in which they are withdrawn from between the needles and lie infront, that is on the open sides, of the needle hooks.

The sinker nebs are used, during the course of the knitting cycle, tohold down previously knitted loops around the shanks of the needles asthe needles rise between the sinkers.

A portion of the sinker adjacent the neb usually forms a knock-over edgewhich pushes the loops lying around the shanks of the needles upwardsoff the tops of the needles as the needles descend again later in theknitting cycle.

The portions of the sinkers which form the knock-over edges usuallyextend in a direction transverse to the row of needles, but in somecases the knock-over edges have been formed by a die-cast bar whichextends parallel to the row of needles and into which the ends of thesinkers adjacent the nebs are cast to fix them together. This form oflongitudinal knock-over edge has not proved very satisfactory becausethe die-cast bars are necessarily soft and gnooves are cut in them bythe threads. The threads eventually tend to jam in these grooves.

According to the present invention a sinker assembly for a fiat warpknitting machine comprises a row of flat faced sinkers mounted face toface with spaces between them, each sinker having a neb projecting fromone edge and pointing towards one end of the sinker, and a rollermounted between each adjacent pair of sinkers and adjacent the ends ofthe sinkers towards which the nebs point, the rollers being rotatableabout a common axis extending along the row of sinkers.

The rollers form a knock-over edge which extends in a direction parallelto the row of needles and this has certain advantages over transverselyextending knock-over edges on the sinkers themselves. Because therollers turn they are not cut by the threads and so the disadvantages ofthe knock-over edge formed by a die-cast bar are overcome. To ensurethat no cutting takes place the rollers may be made of hardened steel orceramic material.

The knitted fabric as it is produced by the knitting elements is drawnoif in a direction away from the backs of the needle books by thedraw-off rollers, or other drawofi mechanism of the knitting machine,and therefore passes directly across the longitudinal knockover edge.This provides a more even drag on the knitted material as it is drawnolf than is provided by transverse edges over which the fabric is drawnin a skew direction.

Preferably, each roller consists of a circular disc having a centralcircular hole and each roller is carried on a circular rod having adiameter substantially less than that of the hole so that the disc ismovable in a plane at right angles to the row of sinkers. With thisarrangement, the sinker assembly can be fixed in the knitting machine insuch a way that the back of the needle hook comes into contact with thecircular disc as the needles descend and the sinker nebs are withdrawnfrom between the needles; that is as the stage or knock-over isapproached in the ice,

knitting cycle. The contact of the backs of the hooks of the needleswith the discs, tends to rotate the discs on their supporting rods.Because the holes in the discs are greater than the diameter of the rod,the discs tend to roll on the rod and this lifts the part of theperiphery of the disc remote from that which is in contact with the backof the needle. This lifting of the disc raises the part of the fabricwhich has just been knitted and which passes over the top of the disc,and greatly assists the knock-over operation.

Two examples of sinker assemblies constructed in accordance with theinvention are illustrated in the accompanying drawings, in which:

FIGURE 1 is a perspective view of one assembly;

FIGURE 2 is a cross-section through a part of the assembly shown inFIGURE 1;

FIGURE 3 is a perspective View of part of another assembly; and

FIGURE 4 is an elevation of the assembly as seen in the direction of thearrow IV in FIGURE 3.

The'assembly shown in FIGURE'I comprises a series of sinkers consistingof flat plates 1 fixed together face to face by being cast into a lightmetal block 2. Each plate 1 has a projecting neb 3 on its upper edge.The plates 1 are fixed together at their left-hand ends, as seen inFIGURES 1 and 2 of the drawings, by a rod 4 which passes through a holein each of the plates.

Mounted on the rod 4 between each adjacent pair of plates 1 is acircular disc 5 having an internal opening 6 with a diameter equal toapproximately twice that of the rod 4.

In use in a fiat warp knitting machine, the assembly is fixed to asinker bar as described in my co-pending appli cation Serial No. 18,039,filed March 28, 1960, now Patent No. 2,988,906. When this is done thesinker assembly is in the position shown in FIGURE 2 of the drawingsrelative to a needle 7 as the needle and sinker reach a stage in theknitting cycle shortly before knock-over takes place.

From the position shown in full lines in FIGURE 2 of the drawings, theback 8 of the hook 9 of the needle 7 moves downwards into the positionshown in chain-dotted lines at 8'. As this happens, the part of the disc5 in contact with the back 8 is pushed downwards and this rolls the disc5 on the rod 4 so that the upper part of its periphery is raised intothe position shown at 5. This upward movement of the top of theperiphery of the disc 5, which forms the knock-over edge of the sinker,lifts the knitted fabric, and with it the last knitted loop lying aroundthe shank of the needle '7, relatively to the needle 7 and expedites theknock-over of the loop.

The discs 5 shown in FIGURES l and 2 of the drawings have cylindricalperipheries and they are a close sliding fit between the plates 1.

In the second example illustrated in FIGURES 3 and 4 of the drawings,the discs 5 are substituted by rollers 10 which are a close rotatablefit on the rod 4. As shown in FIGURE 4 of the drawings, the rollers 10have grooved peripheries 11. Since the rollers 10 are a close fit on therod 4 they are only capable of rotating and cannot roll as do the discs5. Because of the grooves in their peripheries 11, however, they locateand space the threads which pass over them accurately along the rod 4.

I claim:

1. A sinker assembly for a flat warp knitting machine, the assemblycomprising a now of flat faced sinkers mounted face to face*with spacesbetween them, each sinker having a neb projecting from one edge andpointing towards one end of the sinker, and a roller mounted betweenthose ends of each adjacent pair of sinkers towards which the nebspoint, the rollers being rotatable about a common axis extending alongthe row of sinkers.

2. An assembly according to claim 1, in which each roller consists of acircular disc having a central circular hole and is carried on acircular rod having a diameter substantially less than that of the holeso that the disc is movable in a plane at right angles to the row ofsinkers.

3. A sinker assembly for a flap warp knitting machine, said assemblycomprising a plurality of flap elongated sinker plates, each of saidplates comprising a first end portion, a second end portion, alongitudinal edge extending between said end portions, and a neb portionprojecting from said edge intermediate said end portions and pointingtowards said first end portion, means interconnecting said second endportions of said plates whereby said plates are fixed together in a rowin spaced apart face to face relation with said neb portions inalignment with each other, a plurality of rollers, one roller beinglocated between the first end portions of each adjacent pair of saidplates, and means carried by said sinker plates on which said rollersare mounted for rotation about a common axis.

4. A sinker assembly according to claim 3, wherein each of said rollersconsists of a circular disc having a central circular hole and saidmounting means consists of a circular rod extending through said firstend portions and through said holes, said holes being of greaterdiameter than said rod whereby said discs are movable in a plane atright angles to said row.

5. An assembly according to claim 3, in which said rollers each have aperipheral groove.

6. In a fiat warp knitting machine including a row of hooked needles theimprovement consisting of a sinker assembly comprising a plurality offlat elongated sinker plates one between each adjacent pair of saidneedles, each of said plates comprising a first end portion, a secondend portion, a longitudinal edge extending between said end portions anda neb portion projecting from said edge intermediate said end portionsand pointing towards said first end portion, said nebs being located onthe open sides of said needle hooks, means interconnecting said secondend portions of said plates whereby said plates are fixed together in arow in spaced apart face to face relation with said neb portions inalignment with each other, a plurality of rollers, one roller beinglocated between said first end portions of each adjacent pair of saidplates, and means carried by said plates on which said rollers aremounted for rotation about a common axis lying on the closed sides ofsaid needle hooks.

7. A fiat warp knitting machine according to claim 6, wherein each ofsaid rollers consists of a circular disc having a central circular holeand said mounting means consists of a circular rod extending throughsaid first end portions and through said holes, said holes being ofgreater diameter than said rod whereby said discs are movable in a planeat right angles to said row.

8. A fiat warp knitting machine according to claim 6, in which saidrollers each have a peripheral groove.

References Cited in the tile of this patent UNITED STATES PATENTS2,682,163 Stat]? et a1 June 29, 1954 2,749,730 Noe June 12, 1956 FOREIGNPATENTS 147,056 Great Britain Dec. 20, 1920

